Abrasive belt tool



Aug. 4, 1953 J. Y. BLAZEK ABRAsIvE BELT Toor.

Filed June 14, 1950 OCDQ 5 .K A mu .d A M mm 4 u. N H .w w i Y B. z 2 Z3 al f1.- -.-J I Pi 1L F l 8 3 z f1 ,3 um M 8 r/J/ m l` IU. w -ill 0 .dn l l W a U Il M E fr ,./l/l/l//f d l I 7 e e EL ,a 3 7 5 e .e 3L |14 3Patented Aug. 4, 1953 ABRAsIvE BELT 'rooL .lohn Blazek, Maple Heights,Ohio, assignor to Lempco Products, Inc., Bedford, Ohio, a corporation ofOhio Application June'14, 1950, Serial No. 167,978

3 Claims.

The invention relates to abrasive tools and particularly to tools of thepower driven abrasive belt class.

In various arts the surface left on metal by an abrasive wheel, cuttingtool or the like, is not smooth enough or ne enough for the usesy towhich it is to be put; and it is desirable to perform a final iinishingoperation thereon bya very ne grained abrasive cloth or paper.

A large class of such surfaces are cylindrical surfaces, for example thebearings of an engine crank shaft. Such surfaces can be rotated in amachine between centers and in the vcase of crank shaft bearings arerotated in themachinethat grinds thein to size; and the invention hasparticular application to finally finishing rotating cylindricalsurfaces; although as will appear hereinafter, it may be applied withadvantage to non-rotary surfaces and to various shapes of sur-f faces.

The actual invention hereof is that set forth in the appended claims.

In general, however, the invention. comprises an abrasive belt,supported on pulleys and driven by an electric motor. Along flight ofbelt is provided between widely spaced pulleys and the said Eight whilerunning on the pulleys is the part of the belt that is applied to thework, whereby the' yielding of the belt flight maires the contact of theabrasive with the work a yielding contact.

The motor, belt and pulleys are mounted in a portable frame of lightweight whereby it mayv be easily brought to the work andoperatedmanually. Handles are provided for both hands of the operator, and sodisposed that the weight of the device is well balanced in his hands,and .so that he can apply the belt iiight to the work with easilycontrolled yieldingT pressure, by a simple rocking movement of thehandles.

Improved means is provided to adjust the tension of the said beltflight, and to permit the belt to be readily removed and replaced whenworn; or to substitute for it one of different grain.

The objects of the invention are:

To provide generally an improved abrasive tool of the class referred to;

To provide an abrasive tool having the mode of operation andconstruction features among others set forth above. f

The invention is fully disclosed in the following description taken inconnection with the accom panying drawing, in which:

Fig. 1 is a side elevational viewof a toolembodying the invention;

Fig. 2 is a top plan view of the embodiment of Fig. 1;

Fig. 3 is a sectional view from the plane 3 3 of Fig. 1 with partsbroken away;

Fig. 4 is a sectional View from the plane 4--4 of Fig. 1 with partsbroken away;

Fig. 5 is a sectional view from the plane 5 5 of Fig. 1 with partsbroken away.

Referring to the drawing, there is shown generally at I a framecomprising an elongated base 2, generally horizontal in the illustratedposition of use, a Vertical leg 3 depending from the rearward end of thebase, an inclined leg 4 depending from the forward end; the frame thusbeing generally of downwardly open U-form, and preferably all in thesame plane.

An electric motor 5 is mounted on the frame in the corner where the base2 and leg 3 meet; and with its shaft at right angles to the plane of theframe; and preferably the leg 3 is made separate from the base 2 andboth secured, as by screws 6 to a bracket 'I mounted on the motor byscrews 8 8. v

j'lhe motor 5 drives a crowned belt pulley Ill, preferably covered by asheet metal hood II secured to the frame by some of the screws 6.

Elongated parallel handles I2-I3 are provided .L at opposite ends of themotor 5, and spaced therefrom as shown in Fig. 2; and inclineddownwardly rearwardlyy as shown in Fig. 1. The preferred construction isto bend a piece of round rod into U-shape, with parallel legs I ll-I 4and to weld the closed end I5 of the U to the top of manually operableset screw 22. A crowned belt pulley 23 is mounted to rotate on thebracket 2l,v

by an axial bolt 24 of a bearing, and the bearing proper may be a ballbearing of well known type within the pulley and not shown.

On the frame end portion 4, a sheet metal bracket 25 is welded andmounts a crowned pulley 26 by an axial bearing bolt 2l; and this bearingalso is of the well known ball bearing type within the pulley and notshown.

The frame is preferably made from square sec-l tion tubing as shown at 3and 4 in Figs. 3, 4, and 5. This facilitates connecting the motor to it,and keeps the bracket 2l from rotating on the leg 3 and provides a nrmwelded joint for the handle at i6, etc, etc.

The three crowned belt pulleys IU, 23, and 2S are all in planaralignment and a closed belt 28 is mounted on them in triangularconfiguration, and driven by the motor pulley lil, and retained thereonby the crowns of the pulleys in a well known manner.

The pulleys 23 and 2li are disposed so that the belt night 29 betweenthem is at a slight upward forward inclination with respect to the base2.

The belt 28 is a commercial abrasive belt having abrasive on its outerface as indicated at 36; Fig. 5.

The tension of the belt may be adjusted by adjusting the position of thebracket 2l along the leg 3 as will be understood.

From the above description, it will be seen that an operator may gripthe two handles l2-I3 in his two hands at points therealong at which theweight of the motor Ei and of the frame will be supported by his handsand in a substantially balanced condition; that is, the forward portionof the frame including the base 2 and the depending portion i will havea tendency to rock downwardly, by gravity, but will be easilycounteracted by the operator. He can thus easily support the tool withthe working belt flight 2S in a generally horizontal or` upwardlyinclined position, projecting forwardly from him.

To nnish a surface, as referred to, the operator starts the motor E andmanipulates the handles to lay the moving belt night 29 on top of thesure face, preferably at the intermediate part of the belt night 29whereby the belt night will yield or exert a cushioned pressure on thework surface. The operator may adjust this pressure from barely afeather contact pressure to a maximum pressure by simply rocking thehandles, with wrist motion as will be understood, to raseor lower thepulley 2S and the belt night 29 at its intermediate working portion.

The arrangement of the handles and the balance of the weight asdescribed makes the adjustment of vthe pressure on the work by theoperator extremely sensitive.

Besides raising and lowering the belt flight as referred to, theoperator can obviously swing the belt from side to side by the handlesto workv a surface of considerable transverse extent without changingthe position of his body.

By having the handles I2-l3 far apart as shown, the operator can raiseone or lower the other to thereby keep the belt night 29 in nat contactwith the work.

The whole tool may be picked up or laid down conveniently as acompletely self-contained tool.

The belt can be removed at any time to renew it or replace it with afresh one or one of dilferent grain, by loosening the adjusting screw 22and sliding the pulley 23' up along the leg 3; and after putting on anew belt it may be tensioned as desired by the reverse of thisoperation. The belt is readily removable endwise from the pulleys, thedescribed support for them making this possible. The hood Il over thepulley l provides protection to the operator from nying particles, andits use is optional, but whenv utilized may be removed before removingthe belt.

At 3|, Figs. 1 and 2, is indicated a work piece of the kind having acylindrical surface 32 to be finished by the tool, and it is assumedthat it is rotatably supported and rotatably driven by means not shown.

The cushioned yielding of the belt night 29 by pressure applied by th-eoperator is indicated by the broken line position of the belt night at29A.

Changes and modincations may be made in the above described structuresuch as will occur to those skilled in the art and the invention iscomprehensive of all such modifications and changes that come within thescope of the appended claims.

I claim:

l. In a manually portable and operable surface finishing. tool, a framecomprising an elongated base member and a leg generally upright in theposition of use, depending from one end portion of the base member, andthe base member having a depending base portion spaced from the leg; amotor on the frame at the top of the leg; -a nrst belt pulley driven bythe motor; a second belt pulley on a lower portion of the depending leg;and a third belt pulley on the depending base portion; an abrasive beltmounted to run on the three pulleys in triangular configuration drivenby the motor, and having a working belt night extending longitudinallybetween the second and third pulleys for working a surface thereunder;an adjustment for the second pulley to change its position on the leg totension the belt; a pair of elongated substantially parallel side byside handles mounted on the frame, spaced transversely with respecty tothe longitudinal direction of the working belt flight and at oppositesides of the motor, on which the weight of the motor and frame ismanually supported and substantially balanced when gripped in the handsof an operator; and the handles disposed so that the working belt flightextends longitudinally away from both handles, and so that when thehandles are both rocked in unison around a common handie axistransversely of the longitudinal direction of the working belt night,the belt night will rock bodily around the axis toward and from the worksurface.

2. In a manually portable and operable surface finishing tool, a framecomprising an elongated base portion extending forwardly and rearwardlyin the position of use; and -a leg depending from a rearward portionthereof; a nrst and a second belt pulley mounted on a lower portion ofthe leg and on a forward portion of the forwardly and rearwardlyextending base portion respectively; a motor mounted on a rearwardportion of the base portion, above the nrst pulley and driving a thirdbelt pulley; an abrasive belt of triangular configuration running on thethree pulleys and having a working belt night extending longitudinally'forwardly and rearwardly between the first and second pulleys forfinishing a work surface thereunder; a pair of spaced apart handlessecured to a rearward part of the frame and both above the correspondingrearward end of the working belt night for manually supporting theframe, motor and belt, and the working belt night extending forwardlylongitudinally away from both handles; the parts arranged so that thehandles may be manually rocked in unison about a common handle axistransverse to the rearward end of the Working belt flight and when sorocked the Working belt flight will rock bodily about said handle axistoward and from the work surface.

3. A manually portable and operable surface nnishing tool comprising: aframe rotatably supporting spaced pulleys; an abrasive belt on thel`pulleys comprising a working belt flight extend- 5 g longitudinallybetween the pulleys; a belt driving motor on the frame; a pair ofside-byside spaced handles on the frame for manually supporting theframe, motor and belt; the handles disposed so that when the belt flightis in a position of use to Work a surface thereunder, the handles areabove one end portion of the belt iiight and the belt ight extendslongitudinally away from the handles, and so that when both handles aremanually rocked in unison in the same direction about an axis transverseto the belt iiight, the belt ight is rocked bodily about said axistoward and from the surface to be worked.

JOHN Y. BLAZEK.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Warner Dec. 27, 1910 Drury Dec. 31, 1912 Erickson Oct. 27,1931 Hardy May 3, 1938 Fowler Apr. 30, 1940 Fowler Apr. 14, 1942

